You can complete your notes by adding attachments.
Please click + on the toolbar at the top of the page and choose Add Attachment or simply drag&drop a file onto Outline page.
Attached files can be opened with corresponding third-party apps to be viewed.
NOTE: Changes you might apply to such files after attaching them won't get saved. Files
are added in their current state which cannot be modified.
To save the changes you've made, reattach the file to your Outline page.